Speaking Politics word of the week: bounce

A post-convention bounce in the polls can happen, but it's usually fleeting.

Bounce: A presidential candidate’s post-convention rise – generally temporary – in polls.

Like quite a few other political words – “borked” and “sherpa” come readily to mind – “bounce” is popular because it’s short, vivid, and fun to say. It already has frequently worked its way into coverage of this week’s Republican convention and to a far lesser extent, the ensuing Democratic one.

Polling expert Nate Silver has determined that the bounce “begins to manifest itself in earnest as of about the third day of the convention.” After that, he said, “the bounce accelerates quickly, peaking approximately 6-7 days from the start of the convention – that is, the weekend afterward, if the convention runs from Monday through Thursday. It then dissipates in a roughly linear fashion over the next 3-4 weeks.”

The late language guru William Safire traced the phrase’s origin to 1980, when Jody Powell, who was President Jimmy Carter’s spokesman, described the 10-percentage-point jump after that year’s Democratic event as “the post-convention bounce we hoped for.” The bounce, obviously, did not last, with Mr. Carter losing in the fall to Ronald Reagan.

The University of California, Santa Barbara’s American Presidency Project has tracked every post-convention bounce since 1964. Bill Clinton had the biggest overall in 1992, when he left the Democratic National Convention with a 16 percentage point surge in polls.

Mr. Clinton was the beneficiary of a near-flawless convention that year in which he closed his acceptance speech with the now-iconic phrase “I still believe in a place called Hope.” Skeptics scoffed, calling it momentary, but it lasted – Clinton ended up never trailing President George H.W. Bush.

Reagan in 1980 and George W. Bush in 2000 had the largest GOP bounces, with eight percentage points each. Barack Obama’s bounces were smaller – four percentage points in 2008 and two percentage points four years later. (The poll noted that the margin of error on the latter was plus or minus two percentage points, thus rendering the event bounce-less).

The candidates who didn’t bounce: Democrats George McGovern in 1972 (his post-convention polls didn’t move) and John Kerry in 2004 (he dropped one percentage point) as well as Republican Mitt Romney four years ago (he also dipped one percentage point). Needless to say, none of them ended up becoming president.

Chuck McCutcheon writes his “Speaking Politics” blog exclusively for Politics Voices.

Interested in decoding what candidates are saying? Chuck McCutcheon and David Mark’s latest book, “Doubletalk: The Language, Code, and Jargon of a Presidential Election,” is now out.